Clothes dryer needs to be wall mounted in the laundry.

Rang Sam to come and re-attach our clothes dryer to the wall in our 'european' laundry space. One of the mounting brackets had become unattached from the plasterboard wall because the original installation (done by a previous tradesperson via our real estate agent) was incorrectly done by direct attachment to the plasterboard and not via the studs behind the wall (which we didn't realize were even present at this stage). Given that we don't have ready access to tools etc, I naively thought that I would save time and effort by having a 'professional' come and fix it. We explained the situation over the phone, and got a quote for $85 over the phone. Sam turned up, handed me his business card, took one look at the problem, and proceeded to ask me if I had a screwdriver? What kind of tradesperson doesn't walk in the door with his tools in hand? He went to get said tools, banged on the wall a few times, punched a hole in the plasterboard, and then told me he couldn't fix it because there were no studs behind the wall. Granted, he justified this by saying that it would be potentially dangerous to do so. All good and well, but then after punching a hole in the wall and telling me he couldn't do anything, he expected $40 for his troubles. I objected, citing that we had fully explained the problem to him before he came out. He then picked up his 'tools' and promptly walked out. End result? I just bought a $30 studfinder and located 2 studs behind the wall. Err, somehow I would have thought that any tradesman worth his salt would have a studfinder in his tool box. Had I actually paid him the $40, well then I'd really be angry!! Looks as though I'll just fix it myself for probably 1/2 the cost. What a complete waste of time-don't use this clown! (Sam-go buy a studfinder, will you?) Oh, and that business card..? In pieces at the bottom of my garbage bin.